제출 #925275

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
925275		Amirreza_Fakhri	Museum (CEOI17_museum)	C++17	100 / 100	244 ms	171908 KiB

museum

// In the name of the God
#include <bits/stdc++.h>
#define ll long long
// #define int long long
#define pb push_back
#define F first
#define S second
#define mp make_pair
#define pii pair <int, int>
#define smin(x, y) (x) = min((x), (y))
#define smax(x, y) (x) = max((x), (y))
#define all(x) (x).begin(), (x).end()
using namespace std;

const int inf = 1e9+7;
const int mod = 998244353;
const int maxn = 1e4+5;

int n, k, r, cnt[maxn], dp[maxn][maxn][2], tmp[maxn][2];
vector <pii> adj[maxn];

void dfs(int v = r, int p = r) {
    cnt[v] = 1;
    for (pii e : adj[v]) {
        int u = e.F;
        if (u == p) continue;
        dfs(u, v);
        for (int i = 1; i <= cnt[v]; i++) {
            smin(tmp[i][0], dp[v][i][0]);
            smin(tmp[i][1], dp[v][i][1]);
            for (int j = 1; j <= cnt[u]; j++) {
                smin(tmp[i+j][0], dp[v][i][0]+dp[u][j][0]+e.S*2);
                smin(tmp[i+j][1],
                min(dp[v][i][0]+dp[u][j][1]+e.S, dp[v][i][1]+dp[u][j][0]+e.S*2));
            }
        }
        cnt[v] += cnt[u];
        for (int i = 1; i <= cnt[v]; i++) {
            dp[v][i][0] = tmp[i][0], dp[v][i][1] = tmp[i][1];
            tmp[i][0] = tmp[i][1] = inf;
        }
    }
}

int32_t main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    memset(tmp, 63, sizeof tmp);
    cin >> n >> k >> r;
    r--;
    for (int i = 1; i < n; i++) {
        int v, u, w; cin >> v >> u >> w;
        adj[--v].pb(mp(--u, w));
        adj[u].pb(mp(v, w));
    }
    dfs();
    cout << dp[r][k][1] << '\n';
    // for (int i = 1; i <= n; i++) cout << dp[r][i][1] << '\n';
    return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 25 / 25
• Subtask 3: 35 / 35
• Subtask 4: 20 / 20